Refactor optimized in hydrogen only runtime functions.

test/mjsunit/compiler/dead-string-char-code-at.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 13 matching lines @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Flags: --allow-natives-syntax
 
 var S1 = "string1";
 var S2 = "@@string2";
 
 function dead1(a, b) {
-    var x = %StringCharCodeAt(a, 4);
+    var x = %_StringCharCodeAt(a, 4);
     return a; // x is dead code
 }
 
 function dead2(a, b) {
-    var x = %StringCharCodeAt(a, 3);
-    var y = %StringCharCodeAt(b, 1);
+    var x = %_StringCharCodeAt(a, 3);
+    var y = %_StringCharCodeAt(b, 1);
     return a; // x and y are both dead
 }
 
 function dead3(a, b) {
     a = a ? "11" : "12";
     b = b ? "13" : "14";
-    var x = %StringCharCodeAt(a, 2);
-    var y = %StringCharCodeAt(b, 0);
+    var x = %_StringCharCodeAt(a, 2);
+    var y = %_StringCharCodeAt(b, 0);
     return a; // x and y are both dead
 }
 
 function test() {
   var S3 = S1 + S2;
 
   assertEquals(S1, dead1(S1, S2));
   assertEquals(S1, dead2(S1, S2));
   assertEquals("11", dead3(S1, S2));
 
@@ skipping 13 matching lines @@
   assertEquals("true", dead2("true", S3));
   assertEquals("11", dead3("true", 0));
 }
 
 test();
 test();
 %OptimizeFunctionOnNextCall(dead1);
 %OptimizeFunctionOnNextCall(dead2);
 %OptimizeFunctionOnNextCall(dead3);
 test();